Pile-anchor reinforced slopes show to have better seismic resistance performance than other traditional supporting structures. However, their bearing mechanisms are not yet fully understood. In this study, dynamic centrifuge model tests are carried out to study the dynamic response and synergistic mechanism of rock slope reinforced by pile-anchor composite structures under seismic loading. The centrifuge model is devised by following the scaling principle, and the properties of the model materials are determined by laboratory tests. Some parameter studies are carried out considering the anchor elastic modulus, pile bending stiffness, and pile embedding depth. The test results are discussed in terms of the failure mechanism of the slope to help better understand the synergistic mechanism of the pile-anchor structure in seismically active areas.